自我注入與外部注入的比較

首先，對於自我注入的系統而言，由於系統中具有一個共振腔，

使得系統架構相當複雜，使用元件較多使得系統的價格也相對昂貴。

其次，自我注入的注入光源也是脈衝訊號，因此注入的脈衝必須要與

FP-LD 的調變頻率匹配，否則注入效率將會降低，影響系統的效能。

縱然我們可以在系統中加入一個可調光遲延器來解決此一問題，然而 要微調光延遲器來對應不同波長的訊號，在系統操作上也是比較困難 的部分。然而由於加入了光延遲器，不論是在可調範圍、輸出脈衝的 脈衝寬度以及 SMSR 都有相當好的表現。

對於本論文所提出的外部注入的系統而言，系統架構非常簡單，

主要只有使用三個元件，包含：FP-LD、可調濾波器以及 EDFA。架 構非常的簡單，使得系統的成本相當低廉。而 EDFA 的 ASE 是一連 續的寬頻光源，因此不會有注入不匹配的問題，使得系統操作難度降 低許多。然而 ASE 不同波長具有不同的功率，使得系統輸出的脈衝 訊號也會隨著 ASE 功率變化而變動，無法如自我注入的脈衝雷射獲 得良好的控制。因此不論是在可調範圍、輸出脈衝的脈衝寬度以及 SMSR 的表現上不如前述的共振腔雷射出色。

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